Hydraulic press,more particularly for treating metals by shaping



Filed June 6, 1967 y 7, 1970 G. s. FORICHON 3,518,869

HYDRAULIC PRESS, MORE PARTICULARLY FOR TREATING METALS BY SHAPING 5Sheets-Sheet 1 Fig;

WKJMM $11 121 July 7, 1970 G. s. FORICHON 3,518,869

HYDRAULIC PRESS, MORE PARTICULARLY FOR TREATING METALS BY SHAPING FiledJune 6, 1967 5 Sheets-Sheet 2 WW by July 7, 1970 G. s. FORICHON3,513,369

HYDRAULIC PRESS, MORE PARTICULARLY FOR TREATING METALS BY SHAPING FiledJune 6, 196'? 5 Sheets-Sheet 5 max 70E WM 5% A, y/t wlwm July 7, 1970 G.s. FORICHON 3,518,869

HYDRAULIC PRESS, MORE PARTICULARLY FOR TREATING METALS BY SHAPING FiledJune 6, 1967 5 Sheets-Sheet L 8 4g- 0; o 5 15 mm //VVE/V TOR WWM , WMWMFiled June 6, 1967 July 7, 1970 e. s. FORICHON 3,518,369

HYDRAULIC PRESS, MORE PARTICULARLY FOR TREATING METALS BY SHAPING 5Sheets-Sheet 5 United States Patent 3,518,869 HYDRAULIC PRESS, MOREPARTICULARLY FOR TREATING METALS BY SHAIING Gaston Sebastien Fori'chon,177 Rue de Billancourt, Boulogne, France Filed June 6, 1967, Ser. No.643,903 Claims priority, application France, Mar. 30, 1967,

Int. Cl. rizl 9/12 US. Cl. 72453 6 Claims ABSTRACT OF THE DISCLOSUREThere are a large number of hydraulic presses on the market today ofsmall, medium and large size, that are generally arranged so that theirwork cycle is totally subordinated to the employing of a work fluid.

Thus, the pressure of a work fluid is used, both for the approach stageof the press plate as for the work stage itself.

With this idea in mind, FIG. 1 illustrates by means of diagrams thevarious stages of the operating cycle of known hydraulic presses. To theleft of the diagram the press punch 1 is diagrammatized, as well as thebillet 2, before treatment.

Before starting up the hydraulic press, the press piston, and hence thepunch, are in the top position, i.e., the pressure chamber, delimitedbetween said piston and its cylinder, is reduced to a minimum volume.The billet 2 for treatment is placed on the lower female die plate andthe press is ready for operating.

Seeing that this refers to a press working by deformation of the metal,it is necessary, in a first period, called the approach stage, to bringthe punch as quickly as possible, into proximity with the billet, then,in a second period called the slowing-down stage, brake the punch so asprogressively to bring it againt the top face of the billet.

These two stages of approach and slowing-down A and R are entirelydetermined by the delivery of the work fluid, i.e., that the presspiston is impelled downwards by the delivery of the fluid, whichdelivery must be the greater as the pressure chamber, delimited betweenthe piston of the press and the cylinder, progressively increases involume as the piston descends.

On this account, and seeing that it refers to a large gauge press, itfrequently occurs that the volume of pressure chamber is veryconsiderable, thus necessitating a considerable loss of time, due to thefilling of this compression chamber by a fluid which must also becompressed.

The slowing-down stage is also detrimental to the speed of operating thepress, owing to braking the punch which, before all things, is necessaryif we wish to avoid an abrupt impact of said punch on the billet, whichmay lead to the damaging of the tools.

It is only after these two preliminary stages A and R, that the workstage T really begins.

This Work stage is again also determined by an increase of the pressureof the fluid, so that the punch deforms the billet for modelling it intothe required shape.

When the work stage T is finished, a contact, generally situated on thecourse of the press piston, inverts the electro-valves which effect thedecompression of the fluid, initially compressed to comply with theapproach stage A and to the work stage T. Actually, it is obvious thatit is necessary to ease off the compressed fluid, instead of abruptlyreleasing it, owing to the heavy pressures to which said fluid issubjected.

When the fluid is sufliciently decompressed, the pressure prevailing inthe chamber situated behind the rear face of the press piston thenbecomes less than that exerted under the peripheric shoulder of thepiston, which leads to the upward stage Re of the press piston.

The piston now returns to its initial position. The press is once moreready to operate.

In FIG. 1, displacements D are shown in ordinates, whereas the time Tp,selected as example, is given in abscissae.

In this FIG. 1, the times required for each working stage of the pressare given, by way of example, in seconds, and this, so as subsequentlyto be able to compare these times with those obtained by the pressaccording to the invention.

approach stage A=0.25 slowing-down stage R=0".10

fluid compression stage CF:0.45 work stage T=1".9()

fluid decompression stage DF:0".30 press piston rising stage Re=0.60cycle total 3".6.

It is quite clear from this diagram that a considerable amount of timeis lost in the stages called approach, slowing-down, compression anddecompression of the fluid.

Actually, these four stages, although not directly taking part in thework stage, nevertheless represent in themselves alone, a certain numberof inactive periods, namely, in seconds: 0.25+0".10+O".45+0".30=1".10.

This almost useless time thus has the disadvantage of appreciablyincreasing the duration of the work cycle of the press, which, ofcourse, detracts from its output and hence increases the cost price ofthe parts to be treated.

The invention has the object of obviating these disadvantages andrelates, to this end, to an hydraulic press for treating metals byshaping comprising an upper punch holder plate and a lower female dieholder plate, one of these two plates being mobile in relation to eachother by a hydraulic unit, adjustable mechanical means ensuring themovement of the press piston in the corresponding stroke at its approachstage, i.e., until it abuts on the face of the rough part, these samemechanical means also acting for returning the press piston to itsinitial position.

According to one characteristic of the invention, the mechanical means,determining the approach of the press piston, act in relation with adirect reading device.

According to another characteristic of the invention, the reading deviceconsists of a sliding-gauge in front of which a pointer moves integralwith an intermediate plate, itself in relation with the adjustablemechanical means, which enables instantaneously the ascertaining of theapproach stroke of the press piston.

A press according to the invention is shown by way of non-restrictiveexample in the attached drawings, in which:

FIG. 1 is a diagram corresponding to the work cycle of known presses.

FIG. 2 is a diagram, showing the possibility of comparing the resultsobtained with a press according to 3 the invention in relation to thediagram shown in FIG. 1, and corresponding to the work cycle of knownpresses.

FIG. 3 is a diagrammatical view showing a method of making the pressaccording to the invention, in which the punch is in the top position.

FIG. 4 is a diagrammatical view corresponding to FIG. 3, in which thepunch is in the bottom position.

FIGS. 5 and 6 are diagrammatical views showing an alternativeembodiment.

FIG. 7 is a diagrammatical view of a third method of embodiment.

One of the objects of the invention is to make the maximum reduction ofthe work cycle time of a hydraulic press, so as to increase the rhythmof output of said press, in order to reduce the cost price of treatedarts.

p To this end, the fundamental idea of the invention essentially lies inthe temporary substitution of mechanical means for hydraulic means, moreparticularly in the approach stage of the punch or press piston, whichthus leads to the suppressing of the slowing-down stage F and aconsiderable reduction of the compression and decompression stages ofthe fluid.

Of course, these mechanical means, controlling the movement of the presspiston and hence, the punch, can be of any kind, some examples beinggiven hereafter by way of information, precisely to show thealternatives that can be applied in this field.

(1) According to FIG. 3, the hydraulic press itself consists of ahydraulic unit comprising a tank 3, from which two pumps P and P draw (Pbeing a reduced pressure pump), said pumps being actuated by a Motor Itis from these pumps P and P that the dispatching of the work fluid takesplace, and this by means of a series of electro-valves EVa, EVb, EVc,EVd, which direct the fluid in a direction pertinent to the stage thatit must fulfill at a precise moment, of the work cycle.

The work of these electro-valves is moreover completed by safety valves4, 5 and 6, a pressure gauge contact unit 7 acting for stopping the workoperation, whereas a contact 8 enables, on the other hand, thetriggering of the work stroke.

At a construction level, the press is made of a partially hollowed outframe 9, so as to form a cavity in which the press piston 10 can move ina vertical plane, which delimits, in relation to the cavity 11 formingthe cylinder, a chamber 12, called the pressure chamber.

The piston 10 is also hollowed out so as to accommodate the body of adisplaceable screw 13, whose base is provided with a pinion 15 actuatedby an auxiliary electric motor 16.

This screw 13 is connected to an intermediate plate 17, which comprisesa pointer 18, able to move in front of a graduated scale 19.

The mechanical means causing the movement of the work piston 10, andhence that of the intermediate plate, are made, in this example ofembodiment, from two jointed links 26 and the first one 26 beingconnected to the intermediate plate 17, whereas the second 20 isconnected to the upper punch holder plate 21.

The angle of opening or closing, formed by the two jointed links 20 and20 is ensured by an auxiliary piston 22, connected to the latter by athird link 23, said intermediate piston being movable crosswise in acylinder 24 filled with fluid.

A first adjustment of the position of the jointed links 20 and 20 isensured by a screw stop 25, maneuvered by a second auxiliary motor 26,whose driving pinion 27 constantly meshes with a lock-nut 28 connectedto the screw stop 25.

The guiding and recoil of the upper punch-holder plate 21 is ensured bytwo small jacks, formed by the pistons 29 and 29 which move in thecylinders 30 and 30 The lower female die holder plate of the press 31is, more- 4 over, provided with an ejecter 32 for withdrawing thefinished parts.

In this FIG. 3, the pump P delivers at low pressure (adjusted by thevalve 6 in the rising cylinders 30 and 30 so that the pistons 29 and 29hold the upper punch-holder plate 21 in its top position, in like manneras the auxiliary piston 22 is kept in a retracted position, i.e.,pressed against the screw stop 25, owing to the electrovalve EVd beingpositioned for affording free passage for the fluid delivered by thepump P to the chamber 24 situated in front of the piston 22, the chamber24 situated behind the piston, being, on the contrary, connected by theelectro-valve EVd, to the tank 3, so that the pressure proportionallylowers in this chamber.

FIG. 4 is a view corresponding to FIG. 3, the upper punch holder pressplate being nevertheless in its end of stroke position.

The approach stake of the upper punch-holder plate, which is essentiallyensured by mechanical means, takes place in the following manner:

The position of the electro-valves EVb and EVd shown in FIG. 1 has beeninverted, which leads to:

(a) the introducing of the fluid delivered by the pump P into thechamber 24 situated behind the auxiliary piston 22, and this by means ofducts 33 and 34, put into communication by the electro-valve EVd.

(b) The uniting of the chamber 24 with the tank 3, by the ducts 35 and36 put into communication, here also, by the valve EVd.

(c) The return of the fluid (contained in the cylinders 30 and 30 to thetank 3, by means of ducts 37 and 38, which converge for uniting in aduct 39 going to the tank through the e1ectro-valve EVb.

Thus, the pressure increasing in the chamber 24 and proportionallydiminishing in the chamber 24 the auxiliary piston 22 is moved in thedirection of the arrow F, this movement being the more favorized in thatthe pressure initially prevailing in the cylinders 30 and 30 diminishesand that, hence, the upper punch-holder plate 21 is free to movedownwards (in a vertical plane), the displacement of the auxiliarypiston 22 (in the direction of the arrow F) progressively determiningthe alignment of the links 20 and 20 and hence, the downward movement ofthe upper punch-holder plate 21, until it abuts against the billet 2 tobe treated.

This stroke, forming the approach stage, is pre-regulated by means ofthe stop screw 25, whereas the possible displacement of the intermediateplate 17, whose stroke can be ensured by the auxiliary motor 16, enablesthe upper face of the piston 10 to be correctly pressed against thebottom of the cylinder 11, for preserving, before the piston isdisplaced, a minimum volume in the pressure chamber 12.

The approach travel corresponds to the distance h checked, by directreading on the graduated scale 19, by means of the pointer 18 integralwith the intermediate plate, wheras the distance H (FIG. 3) between theplates is checked by the pointer 18 on the graduated scale 19 When theapproach stage is thus finished, the swiveljoint 43 comes into contactwith the electric switch 8 which inverts the electro-valve EVa; it thensuflices to invert it, from the position it occupies in FIG. 3, to bringit to the position that it occupies in FIG. 4.

We note that in this new position, the electro-valve EVa directlyconnects the pump P to the work chamber 12; situated behind the upperface of the press piston 10, and this by means of ducts 41 and 42 putinto relation.

Form then onwards, the pressure increases in the chamber 12 (whosevolume is reduced to the maximum so as to gain time) and the presspiston 10 is driven downwards.

As the upper punch-holder plate 31 is pressed against the billet to betreated, the hydraulic pressure, ensured in the chamber 12, causes thecrushing, i.e., the deforming of the billet, until the latter is modeledto the required shape, by the cooperation of the die integral with thelower plate 31 and the punch integral with the upper plate 21.

When the shaping operation itself is terminated, the pressure havingreached the required value, the pressuregauge contact 7 immediatelyoperates the inversion of the electro-valves to bring them back to theposition that they originally occupied, i.e., that shown in FIG. 3.

From then onwards, the auxiliary jack 22 recoils, to become pressedagainst the screw stop 25. The articulation points of the links comeclose to each other, corresponding to the rise of the upper punch-holderplate, this action being moreover favorized by the electro-valve EVdwhich enables the fluid to enter, delivered by the pump P into thecylinders 30, and 30 where the lifting pistons 29 and 29 of the plateare found.

Simultaneously with this action, the pump P ensures, by means of theduct 44, the working of the ejector 32 which enables the shaped part tobe withdrawn.

(2) FIGS. 5 and 6 show an alternative embodiment, in which it is not theupper punch-holder plate 21 that is displaced by mechanical means, buton the contrary, the lower female die-holder plate 31.

On the other hand, the links, which, here again, determine the approachstage of the plate, are no longer two in number, but four, symmetricallydistributed so as to enable a regular ascensional displacement in ahorizontal plane, of the press plate 31.

In addition, the screw stop 25 is, according to this embodiment, nolonger driven as in FIGS. 3 and 4 by means of an intermediate motor 26,but by hand by means of a winch 45.

At the top part of the press there is an adjustment screw 13, but thisis no longer actuated by an auxiliary motor 16, as in FIGS. 3 and 4, butby means of a nut 46, represented by a tangent wheel, that can beoperated by a worm 47 and its winch 48.

The punch-holder plate 21 is moreover returned to the top position byrecoil pistons 48 and 48 which move in cylinders 49 and 49 made in theframe of the machine.

As in FIGS. 3 and 4, the auxiliary piston 22 ensures, by moving in thedirection of the arrow F, the alignment of the links 20 20 and 20 whichdetermines the displacement of the female die-holder lower plate 31,whose travel corresponds to the approach stage h, checked by directreading on the graduated scale 19, by means of the pointer 12 integralwith the lower female-die-holder plate 31. The distance H between theplates is always checked by a pointer 18, moving in front of theslidinggauge 19,.

When the female die carried by the press plate 31 is pressed against thebillet to be treated 2, which corresponds to the alignment of the links20 20 20 20 and the engaging of the switch 8, one acts on theelectrovalve EVa, shown in FIGS. 3 and 4, which ensures the sending ofthe fluid delivered by the pump P into the pressure chamber 10, thuseffecting the shaping of the part to be obtained.

In this embodiment, the ejector 32 need not be driven, and in this caseit is the return of the lower female dieholder plate 31 which ensuresthe ejecting of the finished part.

At the end of this operation, the inverting of the electrovalves iseffected by the pressure-gauge contact unit 7, as in FIG. 4.

(3) Finally, FIG. 7 shows another alternative embodiment, in which thelinks of the knuckle-joint type are replaced by a high-speed screw 50,this screw being maneuvered by an auxiliary motor 51 (electric orhydraulic) whose driving pinion 52 continually meshes with a toothedcrown wheel 53, integral with the screw 50 of the punch-holder upperpress piston 21.

The remainder of the working of this alternative em- 6 bodiment isidentical to that shown in FIGS. 3 and 4, with the exception that thedrive of the work stage is not ensured by the aligned position of thelinks acting on the contact 8, but by a projecting cam 54 placed on thecourse of the switch 8.

This switch 8 must be positioned so as to start up the work operation atthe end of the approach travel.

These various alternative embodiments show that the invention is notrestricted to the mechanical means used for rapidly obtaining theapproach of the punch in relation to the billet to be treated, but thatthey can be varied to infinity, Without going outside of the scope ofthe invention for that purpose.

Thus, and by the mechanical means employed, we obtain an appreciablereduction in the work cycle time, as explained in FIG. 2.

The diagram of this figure, which shows, in abcissae the operation timeTP, and in ordinates, the movements of the tool, shows that the timesinitially necessary for compressing the fluid, for that the timesinitially necessary for compressing the fluid, for the approach andslowing-down of the punch, are suppressed, that of the decompression ofthe fluid is very greatly reduced owing to the minimum of fluid solelyused for the work, which, for a press identical to that shown in FIG. 1,enables the following times to be obtained:

approach stage A=0".20 work time T=1".90, decompression Df=0.10 raisingtime Re=0.20

The addition of these times shows that the total time Tt has dropped to2".4, instead of 3".6, which, on the complete cycle, enables a gain oftime T G of 1".2 to be obtained, being A.

This is the more interesting seeing that the power, which Was, up tillthen necessary for compressing the work fluid in the voluminous chamberleft by the displacement of the piston, has been partly suppressed, fromwhich it results that one can, by means of the press according to theinvention, not only considerably reduce the work cycle time, but alsothe power of the press.

Of course, the invention is not restricted to the examples of embodimentdescribed and shown above, for which other alternatives can be provided,without going outside of the scope of the invention for that purpose.

What I claim is:

1. A hydraulic press comprising,

first and second holder plates adapted for relative movement from anopen position to an approach position of reduced separation, and fromsaid approach position to a closed position of yet further reducedseparation,

approach-recoil drive means for effecting approach movement between saidopen position and said approach position and for effecting recoilmovement between said approach position and said open posiion,

workk-stroke drive means for effecting work-stroke movement between saidapproach position and said closed position,

adjustable control means for determining the amplitude of movementbetween said open position and said approach position and fordetermining the separation of said holder plates at said approachposition, and indicator means to provide a visual indication of thesetting of said control means.

2. The press of claim 1 wherein said work-stroke drive means comprises ahydraulic cylinder and a cooperating piston,

said piston is connected to said first holder plate through a firstadjustable linkage and having a second linkage capable of variablepositioning,

said first linkage serving to determine the separation of said holderplates at said approach position, said secnd linkage being controlled bysaid approach-recoil drive means,

said control means comprising means to determine amplitude of variationin positioning of said second linkage produced by operation of saidapproach-recoil drive means, said indicator means comprising a firstvisual indicator for indicating the amplitude of said approach movementand a second visual indicator for indicating the amplitude of saidwork-stroke movement.

3. The press of claim 2 wherein said indicator means comprises a firstpointer integral with said first holder plate and adapted to indicatethe absolute position of said plate with respect to said press, and asecond pointer integral with said piston and adapted to indicate therelative separation of said piston and said first holder plate.

4. The press of claim 2 wherein said approach-recoil drive meanscomprises an auxiliary hydraulic cylinder, a cooperating auxiliarypiston, and an adjustment screw to regulate the initial position of saidauxiliary piston and to thereby determine the amplitude of said approachmovement.

5. The press of claim 1 wherein said work-stroke drive means comprises ahydraulic cylinder and a cooperating piston,

said piston is connected to said first holder plate through anadjustable linkage,

said second holder plate is driven by said approach-recoil drive means,

said indicator means comprises a first pointer integral 3 with saidfirst holder plate, and a second pointer integral with said secondholder plate.

6. The press of claim 5 wherein said approach recoil drive meanscomprise a plurality of articulated links connecting said second holderplate to the frame of said press and actuated by a hydraulic jack havinga piston adapted to have its initial position manually pre-regulated.

References Cited UNITED STATES PATENTS 1,007,792 11/1911 Orton -2721,696,849 12/ 1928 Kelleher 72-451 1,956,658 5/1934 Schmidt 72-4512,087,811 7/ 1937 Patrick 72-451 2,339,855 1/1944 Hodil 72-454 2,353,8957/1944 Mursch 72-449 2,962,960 12/1960 Salter 100-256 3,162,232 12/1964Munschauer 72-441 3,373,596 3/ 1968 Moeller 72-453 FOREIGN PATENTS782,948 9/ 1957 Great Britain.

CHARLES W. LANHAM, Primary Examiner G. P. CROSBY, Assistant Examiner US.Cl. X.R.

